Semiconductor devices and their peripheral termination

A semiconductor device comprising a semiconductor body that includes a voltage-sustaining zone between first and second device regions adjacent to respective first and second opposite surfaces of the body, the device regions having respective electrode connections, and trenched field-shaping regions including a resistive path that extends in trenches through the voltage-sustaining zone to the second device region, the trenches extending into the body from the first surface, the voltage-sustaining zone being so dimensioned and doped between the trenched field-shaping regions as to be depleted of free charge carriers between the trenched field-shaping regions in a voltage-blocking mode of operation, characterised in that the voltage-sustaining zone and the trenched field-shaping regions are present in both an active device area between the first and second device regions and in a peripheral area that extends around the periphery of the active area, and in that a further resistive path extends across the first surface, outwardly over the peripheral area to provide a potential divider that is connected respectively to successive underlying trenched field-shaping regions in the peripheral area thereby grading the potential applied by the successive trenched field-shaping regions in the peripheral area of the voltage-sustaining zone.